The latest in a series of bizarre British weather phenomena is a rain of fish. It may sound like the stuff of legend, but such events are increasingly well documented.

On Wednesday, the village of Knighton, in Powys, was reported to have endured such a fishy deluge. Not a story easily believed - an odd site for a Biblical-style plague, one might think, perhaps to be followed by the waters of the nearby River Teme running red with blood?

But in fact, as the Met Office explains, such occurrences are not as uncommon as they may sound. Not only are they not quite the miraculous events that they seem, rains of fish - and other even more surprising objects - are reported with some frequency.

1. Fish are picked up from lake

2. Cloud moves over urban area and drops fish

They even provided the inspiration for some of the events in the 1999 Paul Anderson film Magnolia, which went to the extreme of having a diver falling from the sky.

That may be going too far, assures a Met Office spokesman. Fish are the most common thing to have rained down on you - other than rain itself, of course. Rains of frogs have also been known, as have such strange items as tomatoes and even lumps of coal.

Hail, Caesar: Pliny reported a hail of frogs

The phenomenon can be explained simply: given strong enough winds, in thunderstorms for example, small whirlwinds and mini-tornadoes may form. When these travel over water any small items of debris in their path, such as fish or frogs, may be picked up and carried for up to several miles.

Sooner or later, the clouds carrying them will open and drop their strange cargo - resulting in a hail of fish, frogs or whatever the winds happened to pick up.

Weird rains are not limited to Britain - they have been recorded all over the world, throughout the ages. Pliny the Elder, writing in the first century AD, mentioned storms of frogs and fish.

Some believe that these events may give a clue to the origin of the plague of frogs recorded in the Book of Exodus. Two US scientists have come up with an explanation of the 10 plagues of Egypt as a series of linked natural disasters - each following as a result of the other.

So perhaps the residents of Knighton should continue to keep a nervous eye on the river water.